1. Field of the Invention
The present invention relates to an apparatus and a method for detecting damage to linear guide.
2. Description of the Related Art
In a robot system including a robot used to convey an article, etc., a linear guide may be used as a traveling unit for moving the robot (e.g., see JP H07-178690 A).
In order to detect an abnormality of a linear guide, a technique for utilizing a current value of a motor for driving a slide (or a traveling part) of the linear guide is well known (e.g., see JP H07-178690 A or WO 2006/001479 A1). On the other hand, a technique for sensing an abnormality of the linear guide, by detecting or monitoring the vibration and temperature of the linear guide, is well known (e.g., see JP 2003-307230 A).
The current value of the motor for driving the slide of the linear guide is changed (usually, is increased) when the slide or a guide rail of the linear guide is damaged. In addition, the current value of the motor may be changed when an abnormality occurs in a component. (e.g., a rack gear, a speed reducer, or a motor) other than the slide or the guide rail. Therefore, when using the current value of the motor, it is difficult to correctly detect only the damage to the slide or the guide rail.
On the other hand, in order to detect or monitor the vibration and temperature, a sensor capable of simultaneously detecting the vibration and temperature is necessary, whereby an apparatus including the linear guide may be complicated and costly. Thus, a technique for detecting the damage to the slide or the guide rail of the linear guide used as the traveling unit for the robot, by using a simple configuration, is desired.